Poor mileage and will not start after two hours

This sounds like your issue happens after you put fuel in the vehicle. If that is the case then most likely you have a faulty purge control valve and possibly raw fuel in the charcoal canister. This is what causes the valve to fail so I attached the info for this. Let me know what questions you have but this valve is responsible for allowing vapor from the tank into the engine so that it is not omitted to the atmosphere.

Here is a guide that talks about other common causes of a stall:

https://www.2carpros.com/articles/engine-stalls

I attached the info about the purge. Let me know what questions you have and we can go from there. Thanks

Hi:
Is the check engine light staying on when it runs? Is there any black or dark gray smoke from the exhaust? Does the vehicle, other than fuel mileage, seem to run properly? Have simple thing such as the air filter been checked? If it's plugged, it will cause low fuel mileage. Here is a link that shows how one is replaced.

https://www.2carpros.com/articles/how-to-replace-a-car-air-filter

Let me know if there is anything you can think of that may help me diagnose what is happening.

Take care,
Joe